Santorini's last eruption was in 1950, but as recently as 2012 there was a "period of unrest", says Isobel. Magma flowed into the volcanoes' chambers and the islands "swelled up".

Popular holiday destination at risk of 'really destructive' eruption Santorini, an island in the southern Aegean Sea, is one of Greece 's leading holiday destinations attracting more than three ...